remove Events from bevy_app, they now live in bevy_ecs (#4066)

# Objective

Fixes #4064.

## Solution

- remove Events from bevy_app

crates/bevy_app/src/app.rs

@@ -1,8 +1,7 @@
-use crate::{
-    CoreStage, Events, Plugin, PluginGroup, PluginGroupBuilder, StartupSchedule, StartupStage,
-};
+use crate::{CoreStage, Plugin, PluginGroup, PluginGroupBuilder, StartupSchedule, StartupStage};
 pub use bevy_derive::AppLabel;
 use bevy_ecs::{
+    event::Events,
     prelude::{FromWorld, IntoExclusiveSystem},
     schedule::{
         IntoSystemDescriptor, RunOnce, Schedule, Stage, StageLabel, State, StateData, SystemSet,

crates/bevy_app/src/ci_testing.rs

@@ -12,7 +12,7 @@ pub struct CiTestingConfig {
 fn ci_testing_exit_after(
     mut current_frame: bevy_ecs::prelude::Local<u32>,
     ci_testing_config: bevy_ecs::prelude::Res<CiTestingConfig>,
-    mut app_exit_events: crate::EventWriter<AppExit>,
+    mut app_exit_events: bevy_ecs::event::EventWriter<AppExit>,
 ) {
     if let Some(exit_after) = ci_testing_config.exit_after {
         if *current_frame > exit_after {

crates/bevy_app/src/lib.rs

@@ -12,7 +12,6 @@ mod ci_testing;
 
 pub use app::*;
 pub use bevy_derive::DynamicPlugin;
-pub use bevy_ecs::event::*;
 pub use plugin::*;
 pub use plugin_group::*;
 pub use schedule_runner::*;

crates/bevy_app/src/schedule_runner.rs

@@ -1,9 +1,8 @@
 use crate::{
     app::{App, AppExit},
     plugin::Plugin,
-    ManualEventReader,
 };
-use bevy_ecs::event::Events;
+use bevy_ecs::event::{Events, ManualEventReader};
 use bevy_utils::{Duration, Instant};
 
 #[cfg(target_arch = "wasm32")]

crates/bevy_asset/src/assets.rs

@@ -2,8 +2,12 @@ use crate::{
     update_asset_storage_system, Asset, AssetLoader, AssetServer, AssetStage, Handle, HandleId,
     RefChange,
 };
-use bevy_app::{App, EventWriter, Events};
-use bevy_ecs::{system::ResMut, world::FromWorld};
+use bevy_app::App;
+use bevy_ecs::{
+    event::{EventWriter, Events},
+    system::ResMut,
+    world::FromWorld,
+};
 use bevy_utils::HashMap;
 use crossbeam_channel::Sender;
 use std::fmt::Debug;

crates/bevy_asset/src/debug_asset_server.rs

@@ -1,5 +1,6 @@
-use bevy_app::{App, Events, Plugin};
+use bevy_app::{App, Plugin};
 use bevy_ecs::{
+    event::Events,
     schedule::SystemLabel,
     system::{NonSendMut, Res, ResMut, SystemState},
 };

crates/bevy_gilrs/src/gilrs_system.rs

@@ -1,5 +1,5 @@
 use crate::converter::{convert_axis, convert_button, convert_gamepad_id};
-use bevy_app::EventWriter;
+use bevy_ecs::event::EventWriter;
 use bevy_ecs::system::{NonSend, NonSendMut};
 use bevy_input::{gamepad::GamepadEventRaw, prelude::*};
 use gilrs::{EventType, Gilrs};

crates/bevy_input/src/gamepad.rs

@@ -1,5 +1,5 @@
 use crate::{Axis, Input};
-use bevy_app::{EventReader, EventWriter};
+use bevy_ecs::event::{EventReader, EventWriter};
 use bevy_ecs::system::{Res, ResMut};
 use bevy_utils::{tracing::info, HashMap, HashSet};
 

crates/bevy_input/src/keyboard.rs

@@ -1,5 +1,5 @@
 use crate::{ElementState, Input};
-use bevy_app::EventReader;
+use bevy_ecs::event::EventReader;
 use bevy_ecs::system::ResMut;
 
 /// A key input event from a keyboard device

crates/bevy_input/src/touch.rs

@@ -1,4 +1,4 @@
-use bevy_app::EventReader;
+use bevy_ecs::event::EventReader;
 use bevy_ecs::system::ResMut;
 use bevy_math::Vec2;
 use bevy_utils::HashMap;

crates/bevy_render/src/render_resource/pipeline_cache.rs

@@ -7,8 +7,8 @@ use crate::{
     renderer::RenderDevice,
     RenderWorld,
 };
-use bevy_app::EventReader;
 use bevy_asset::{AssetEvent, Assets, Handle};
+use bevy_ecs::event::EventReader;
 use bevy_ecs::system::{Res, ResMut};
 use bevy_utils::{tracing::error, Entry, HashMap, HashSet};
 use std::{hash::Hash, ops::Deref, sync::Arc};

crates/bevy_scene/src/scene_spawner.rs

@@ -1,8 +1,8 @@
 use crate::{DynamicScene, Scene};
-use bevy_app::{Events, ManualEventReader};
 use bevy_asset::{AssetEvent, Assets, Handle};
 use bevy_ecs::{
     entity::{Entity, EntityMap},
+    event::{Events, ManualEventReader},
     reflect::{ReflectComponent, ReflectMapEntities},
     system::Command,
     world::{Mut, World},

crates/bevy_ui/src/flex/mod.rs

@@ -1,9 +1,9 @@
 mod convert;
 
 use crate::{CalculatedSize, Node, Style};
-use bevy_app::EventReader;
 use bevy_ecs::{
     entity::Entity,
+    event::EventReader,
     query::{Changed, FilterFetch, With, Without, WorldQuery},
     system::{Query, Res, ResMut},
 };

crates/bevy_window/Cargo.toml

@@ -11,6 +11,7 @@ keywords = ["bevy"]
 [dependencies]
 # bevy
 bevy_app = { path = "../bevy_app", version = "0.6.0" }
+bevy_ecs = { path = "../bevy_ecs", version = "0.6.0" }
 bevy_math = { path = "../bevy_math", version = "0.6.0" }
 bevy_utils = { path = "../bevy_utils", version = "0.6.0" }
 raw-window-handle = "0.4.2"

crates/bevy_window/src/lib.rs

@@ -20,7 +20,8 @@ pub mod prelude {
     };
 }
 
-use bevy_app::{prelude::*, Events};
+use bevy_app::prelude::*;
+use bevy_ecs::event::Events;
 
 pub struct WindowPlugin {
     pub add_primary_window: bool,

crates/bevy_window/src/system.rs

@@ -1,5 +1,6 @@
 use crate::WindowCloseRequested;
-use bevy_app::{AppExit, EventReader, EventWriter};
+use bevy_app::AppExit;
+use bevy_ecs::event::{EventReader, EventWriter};
 
 pub fn exit_on_window_close_system(
     mut app_exit_events: EventWriter<AppExit>,

crates/bevy_winit/src/lib.rs

@@ -10,8 +10,12 @@ use bevy_input::{
 pub use winit_config::*;
 pub use winit_windows::*;
 
-use bevy_app::{App, AppExit, CoreStage, Events, ManualEventReader, Plugin};
-use bevy_ecs::{system::IntoExclusiveSystem, world::World};
+use bevy_app::{App, AppExit, CoreStage, Plugin};
+use bevy_ecs::{
+    event::{Events, ManualEventReader},
+    system::IntoExclusiveSystem,
+    world::World,
+};
 use bevy_math::{ivec2, DVec2, Vec2};
 use bevy_utils::tracing::{error, trace, warn};
 use bevy_window::{